Motorway

M3 traffic and collisions

The M3 is a motorway of 62.5 miles, from Surrey to Hampshire. This page covers its traffic at 24 DfT count points since 2000 and the collisions police recorded on it.

Last updated
Records analysed
24 count points in 2025
Methodology
View methodology
  • Traffic in 2025 2.1bn vehicle miles
  • Average daily traffic 91,563 vehicles a day, both directions
  • Busiest section 140,751 J13 to J14
  • HGV share 6.2% of vehicle miles
  • Traffic since 2019 −3.5% same count points
  • Collisions, 2021 to 2025 571 5.7 per 100m vehicle miles

How busy is the M3?

On an average day in 2025, 91,563 vehicles passed each point on the M3, counting both directions. The busiest section is J13 to J14 (Hampshire), with 140,751 a day; the quietest listed is A27 to M27 (14), with 25,406.

Busiest sections, 2025

J13 to J14 carries 1.5 times the road’s average flow.

Sections of the M3 with the highest average daily flow, 2025
Section Vehicles a day
J13 to J14 Hampshire · 1.2 mi · HGVs 7.0% 140,751
J12 to J13 Hampshire · 1.7 mi · HGVs 7.6% 130,785
J11 to J12 Hampshire · 3.5 mi · HGVs 7.3% 128,023
J10 to J11 Hampshire · 0.8 mi · HGVs 9.1% 126,216
Kitsmead Lane Flyover with M3 to J3 Surrey · 5.5 mi · HGVs 6.7% 123,417
J4 to J3 Surrey · 4.5 mi · HGVs 5.7% 118,589
At slip road Hampshire · 0.5 mi · HGVs 9.2% 117,668
J12 to Kitsmead Lane Flyover with M3 Surrey · 2.1 mi · HGVs 6.8% 113,905
J9 to J10 Hampshire · 1.4 mi · HGVs 9.4% 110,741
J5 to J6 Hampshire · 4.8 mi · HGVs 5.7% 103,625

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

Surrey to Hampshire · 62.5 miles

Surrey Hampshire
Schematic route: each line joins the junctions at the ends of a DfT count point link.

M3 traffic and collisions by section

18 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 6 short link roads and spurs (2.9 miles) count in the road’s totals but are not listed.

Show all 18 sections Tap a column heading to sort
Sections of the M3 in route order, 2025 traffic
#
1A308 to A316Surrey0.248,2912.9%−11.3%3
2J2 to J1Surrey5.862,8483.0%+11.5%233.7
3J12 to Kitsmead Lane Flyover with M3Surrey2.1113,9056.8%7141.0
4Kitsmead Lane Flyover with M3 to J3Surrey5.5123,4176.7%519.8
5J4 to J3Surrey4.5118,5895.7%−10.1%444.6
6J4 to J4AHampshire2.193,3715.5%−21.2%153.8
7J4A to J5Hampshire7.596,2435.8%−5.2%524.1
8J5 to J6Hampshire4.8103,6255.7%−7.3%525.9
9J7 to J6Hampshire4.994,6246.3%+10.7%263.2
10J7 to J8Hampshire1.2101,8345.9%−1.9%115.3
11J8 to J9Hampshire11.056,1356.3%−8.4%595.5
12J9 to J10Hampshire1.4110,7419.4%+1.7%2610.0
13At slip roadHampshire0.5117,6689.2%−1.1%8
14J10 to J11Hampshire0.8126,2169.1%+1.3%1810.8
15J11 to J12Hampshire3.5128,0237.3%+0.1%516.6
16J12 to J13Hampshire1.7130,7857.6%+0.6%184.7
17J13 to J14Hampshire1.2140,7517.0%+3.0%248.2
18A27 to M27 (14)Hampshire0.925,4061.6%−31.2%5

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the M3 as the first road, placed on the nearest section by their recorded position; rates (per 100 million vehicle miles) are shown for sections of half a mile or more with 10 or more.

M3 traffic by vehicle type

Cars and taxis make up 76.9% of the vehicle miles on the M3. HGVs account for 6.2%, rising to 9.4% on J9 to J10.

Vehicle mix, 2025

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

HGV share of traffic

HGVs as a share of vehicle miles on the M3, by year
Year HGV share
2000 7.6%
2001 7.4%
2002 7.1%
2003 7.3%
2004 7.3%
2005 7.3%
2006 7.2%
2007 7.3%
2008 7.4%
2009 6.7%
2010 6.7%
2011 6.4%
2012 6.4%
2013 6.5%
2014 6.8%
2015 7.0%
2016 7.1%
2017 6.7%
2018 6.8%
2019 6.4%
2020 8.6%
2021 7.6%
2022 6.9%
2023 6.6%
2024 6.4%
2025 6.2%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

M3 traffic trend

Traffic on the M3 came to 2.09 billion vehicle miles in 2025. At the count points present in both years, it is down 3.5% on 2019, before the pandemic, and up 3.2% on 2015.

Vehicle miles a year

Like for like, traffic is up 7.7% on 2000.

Vehicle miles on the M3 each year, the whole road as it was that year
Year Vehicle miles
2000 1.9bn
2001 2.0bn
2002 2.0bn
2003 2.0bn
2004 2.0bn
2005 2.0bn
2006 2.1bn
2007 2.1bn
2008 2.0bn
2009 2.0bn
2010 2.0bn
2011 2.0bn
2012 1.9bn
2013 2.0bn
2014 2.0bn
2015 2.0bn
2016 2.0bn
2017 2.0bn
2018 2.1bn
2019 2.1bn
2020 1.6bn
2021 1.8bn
2022 2.0bn
2023 2.1bn
2024 2.1bn
2025 2.1bn

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the M3, weighted by link length, by year
Year Vehicles a day
2000 86,427
2001 88,746
2002 88,275
2003 87,898
2004 91,078
2005 89,905
2006 92,894
2007 92,498
2008 90,330
2009 88,495
2010 87,918
2011 90,649
2012 86,669
2013 88,328
2014 88,783
2015 89,014
2016 87,978
2017 90,814
2018 92,143
2019 95,096
2020 68,958
2021 80,342
2022 90,004
2023 92,222
2024 91,273
2025 91,563

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

The chart counts the whole road as it was each year, so new or renumbered stretches move it. The percentage changes compare only count points present in both years (87.5% of today’s road for 2019). In 2025, 13 of the 24 count points were counted; DfT estimated the rest from earlier counts and local trends.

M3 collisions

Police recorded 571 collisions with the M3 as the first road from 2021 to 2025, 114 of them fatal or serious. That is 5.7 per 100 million vehicle miles, higher than the 4.9 for all motorways in Great Britain. On average there were 1.8 a year for each mile of road.

Reported collisions by year

Down 26.3% from 2021 to 2025.

Police-reported collisions on the M3 by year: fatal or serious, and slight
Year SlightFatal or serious
2021 8929
2022 10221
2023 9722
2024 9529
2025 7413

Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated

Sections with the highest collision rates

Per 100 million vehicle miles, 2021 to 2025. Sections of half a mile or more with 10 or more collisions.

Collisions per 100 million vehicle miles by section of the M3, 2021 to 2025
Section Per 100m vehicle miles
J12 to Kitsmead Lane Flyover with M3 Surrey · 71 collisions 41.0
J10 to J11 Hampshire · 18 collisions 10.8
J9 to J10 Hampshire · 26 collisions 10.0
Kitsmead Lane Flyover with M3 to J3 Surrey · 51 collisions 9.8
J13 to J14 Hampshire · 24 collisions 8.2
J11 to J12 Hampshire · 51 collisions 6.6
J5 to J6 Hampshire · 52 collisions 5.9
J8 to J9 Hampshire · 59 collisions 5.5

Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated

A further 37 collisions were recorded at junctions where the M3 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 97.5% of the collisions could be placed on a section. How we count collisions

Council areas on the M3

In route order. Each is the highway authority DfT files the count points under.

  • Surrey
  • Hampshire

Planned closures on the M3 in England

National Highways has 13 planned closures on the M3 between 16 September 2026 and 30 September 2026, all of them starting in that period. 4 close a carriageway rather than a lane or slip road, and 12 start between 7pm and 6am.

  • Lane or slip M3 northbound hard shoulder closure (67/2 to 63/3)

    16 Sept, 09:00 to 16:00 Road maintenance

  • Carriageway M3 southbound Jct 5 entry slip road closure

    17 Sept 21:00 to 18 Sept 06:00 Road maintenance

  • Lane or slip M3 Eastbound Jct 3 to Jct 2 Lane 1,2 closure

    17 Sept 22:00 to 19 Sept 06:00 Road maintenance

  • Lane or slip M3 northbound hard shoulder closure (76/1 to 75/5)

    21 Sept 21:00 to 22 Sept 06:00 Road maintenance

  • Carriageway M3 northbound Jct 6 exit slip closure

    21 Sept 21:00 to 22 Sept 06:00 Road maintenance

  • Lane or slip M3 Eastbound Jct 2 to Jct 1 lane 3,2 closure

    24 Sept 22:00 to 25 Sept 05:30 Road maintenance

  • Lane or slip M3 northbound lane 1 and 2 closure (46/9 to 42/9) and entry slip

    25 Sept 20:00 to 26 Sept 06:00 Road maintenance

  • Lane or slip M3 northbound lane 1 and 2 closure (46/9 to 42/9)

    25 Sept 20:00 to 26 Sept 06:00 Road maintenance

5 more planned closures in this period are not shown.

Planned closures only: National Highways can cancel or change them, and closures caused by incidents are not shown. Council roads in England are not covered. Roadworks and closures across the UK

Source:National Highways 2026-09-16 to 2026-09-30 Updated

Data sources and methodology

Datasets used on this page
Figures Source Period Records Updated
Traffic counts and vehicle mix Road traffic statistics (AADF by count point) Department for Transport
Derived statistics UK Motoring
2000 to 2025 24 count points in 2025 15 September 2026
Reported collisions Road safety open data (STATS19) Department for Transport
Derived statistics UK Motoring
2021 to 2025 571 reported collisions 15 September 2026
Planned closures Transport Data Feeds (DATEX II) National Highways 2026-09-16 to 2026-09-30 2,304 planned closure schemes 16 September 2026
  • Annual average daily flow (AADF) is the average number of vehicles passing a point on a typical day of the year, both directions combined.
  • Vehicle miles are AADF multiplied by link length and 365, summed over every count point link on the road.
  • Sections join count point links between junctions, using the link lines in DfT’s major road database.
  • STATS19 covers personal injury collisions reported to the police. Damage-only collisions are not included, and not every injury collision is reported.
  • Serious and slight figures are DfT’s adjusted estimates, which allow for police forces moving to injury-based reporting.
  • Counts of one or two collisions below Great Britain level are shown as “fewer than 3”.

Contains public sector information licensed under the Open Government Licence v3.0.

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